But if I see you through the glass, the object is going on some trajectory, which has got both up and down and horizontal motion.

但是如果我透过窗户看到你,这个物体沿着某个轨迹运动,既有上下,也有水平方向的运动

耶鲁公开课 - 基础物理课程节选

x = 0 plus-- What's the horizontal velocity?

= 0 加上,水平方向的速度是多少

耶鲁公开课 - 基础物理课程节选

So the pink line is going to move towards the vertical, and the blue line is going to move towards the horizontal, and notice that the amount of effort that we generate, goes down dramatically, goes down in this direction.

粉色的线最后会趋向垂直,蓝色的线最后会趋向水平,请大家注意下我们付出的努力,会朝这个方向大幅减少

耶鲁公开课 - 博弈论课程节选

This vector i prime has got a horizontal part, This kind of trigonometry you should know all the time.

矢量 i' 有一个水平方向的分量,这类三角关系你们应该已经很熟悉了

耶鲁公开课 - 基础物理课程节选

Car is traveling with some initial speed v0 in the horizontal direction.

车以 v0 的初速度沿水平方向开出

耶鲁公开课 - 基础物理课程节选

Quite often, it's natural to pick x and y in a certain way, because starting a projectile near the Earth, it makes sense to pick the horizontal as x and vertical as y.

我们经常会很自然地选取 x 轴和 y 轴,因为如果在地表附近做抛物运动,我们通常以水平方向为 x 轴,竖直方向为 y 轴

耶鲁公开课 - 基础物理课程节选